Recoil booster



Jan. 16, 1968 B. TSCHOEPE 3,363,509

RECOIL BOOSTER Filed July '7, 1965 FIGI H62 INVENTOR BRUNO TSCHOEPE BY ila/6,, 6

ATTORNEY United States Patent 3,363,509 RECOIL BOOSTER Bruno Tschoepe, Karlsruhe-Durlach, Germany, assignor to Dynamit Nobel Aktiengesellschaft, Troisdorf, Germany Filed July 7, 1965, Ser. No. 470,294 15 Claims. (Cl. 8914) The present invention relates to a recoil booster for blank cartridge firing or maneuver practice of heavy or very heavy machine guns adapted to recoil in their supports in the mounts thereof.

A recoil booster is already known for machine guns of this type in which a gas collector sleeve having a throttle nozzle is inserted into the propellant charge gas stream. In connection therewith, it has also been proposed already to reduce the masses to be moved during recoil by a subdivision of the barrel into a barrel rear section and a barrel forward section, whereby the gas-collecting sleeve with the throttle nozzle is then accommodated at the rear end of the barrel front section and the latter is displaceably mounted over the barrel rear section. Upon firing, the barrel rear section is thereby thrown backwards for actuation of the automatic gun mechanism by the gas surge dammed up by means of the throttle nozzle within the gas-collecting sleeve. In order that harmful gas shocks and impacts do not occur thereby, the barrel front section, together with the gas-collecting sleeve secured thereon is moveable in the forward direction. In order to avoid with this movement caused by the gas pressure built-up within the gas-collecting sleeve behind the throttle nozzle that the barrel front section strikes with the rear end flange of the gas-collecting sleeve hard against the counter abutment collar formed rigidly at the barrel rear section, a spring is inserted between the barrel rear section and the barrel front section which dampens both the forward movement of the barrel front section as well as the rearward movement of the barrel rear section.

I Such a spring, however, is not only strongly loaded and stressed but is also subjected in the course of its length of life to certain changes by fatigue appearances, etc., whence the operating efliciency has to be carefully supervised at all times which is both complicated and expensive. The present invention is concerned with the task of avoiding the use of such a spring yet maintaining the damping of the movements caused by the built-up gas pressure in the gas-collecting sleeve and to assure the damping action in a completely satisfactory manner.

With a recoil booster having a gas-collecting sleeve provided with a throttling nozzle for blank cartridge test firing or maneuver practice of heavy or very heavy machine guns supported in the mount thereof for recoil movement, whose maneuver barrel is subdivided into a barrel front section provided at its rear end with the gascollecting sleeve and into a barrel rear section displaceably inserted with its front end into the gas-collecting sleeve, the purposes of the present'invention are achieved in that a pre-throttling nozzle is arranged in the forward end of the bore of the barrel rear section.

As compared to an arrangement without a prethrottling nozzle, the inflow of the propellant gases into the space of the gas-collecting sleeve is slowed down by the measure according to the present invention so that there takes place within the gas-collecting sleeve a slower build-up of the pressure effecting by its action on the front end face of the barrel rear section the recoil movement thereof and correspondingly a softer recoil impulse is imparted to the barrel rear section which obviates the arrangement of a spring and its attendant considerable uncertainties for the damping of the recoil movements.

It is known, per se, with recoil boosters for machine 3,363,509 Patented Jan. 16, 1968 intended with these known recoil boosters to dampen the I recoil of sliding masses in a safe and completely effective manner.

Accordingly, it is an object of the present invention to provide a recoil booster for heavy and very heavy automatic guns which obviates by simple means, the aforementioned shortcomings and drawbacks encountered with the prior art constructions.

It is another object of the present invention to provide a recoil booster which obviates the need of any damping springs, yet effectively and reliably dampens the movements of the subdivided barrel sections in such a manner that no hard and sudden impacts occur between these parts.

A further object of the present invention resides in the provision of a recoil booster for very heavy machine guns which assures reliable operation thereof by safely and elfectively damping the recoil of the sliding masses, yet avoids complicated mechanical parts that are subject to changes in the performance characteristics during normal operation.

Still another object of the present invention resides in the provision of a recoil booster for heavy and very heavy machine guns which prevents shocks and impacts in the guns as a result of recoil movements.

These and other objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIGURE 1 is a longitudinal cross-sectional view through the recoil booster in accordance with the present invention with the parts thereof in the position occupied during firing; and

FIGURE 2 is a longitudinal cross-sectional view of the recoil booster similar to FIGURE 1, showing the various parts thereof in the normal rest position. 7

Referring now to the drawing wherein like reference numerals are used throughout the two views to designate like parts, reference numeral 10 designates therein the barrel front section and reference numeral 12 the barrel rear section of the subdivided gun barrel. The bore of the barrel front section 10 is enlarged at the rear end so that the thus-obtained enlarged bore 13 forms a gascollecting sleeve G. The barrel front section 12 is slidably mounted by means of this enlarged gas-collecting sleeve G on the forward end 14 of the barrel rear section 12 which is machined to proper dimensions for that purpose. An external thread is provided along the outer surface of the gas-collecting sleeve G for purposes of the threaded connection of a clamping or retaining nut 23 which, in turn, is again provided rearwardly along its outer surface with an external thread 15 for the threaded connection with a clamping or retaining counter nut 24. The fixed barrel casing of the gun is designated by reference numeral 18 which is provided at the forward end The interior space of the gas-collecting sleeve G is in communication at the front thereof with the bore of the barrel front section 10 by means of a throttling nozzle 16 and a pre-throttling nozzle 17 is disposed forwardly in the bore of the barrel rear section 12. A gas-discharge channel 19 extends radially through the casing of the retaining nut 23 which channel has an extension toward the interior 13 of the gas-collecting sleeve G.

The recoil booster in the presence of only one throttling nozzle would operate as follows:

If a plastic blank cartridge is fired, then the recoil booster is in the position of forward movement. The propellant charge gas stream leaves the cartridge case and enters into the bore of the barrel rear section 12, is dammed up in the gas-collecting sleeve G, and exerts thereby a rearwardly directed impulse on the front face of the barrel rear section 12 so that the latter receives a sufiicient recoil movement which sufiices for the actuation of the automatic mechanism of the gun. This recoil impulse takes place by reason of the sudden damming up of the gas in an impact-like manner which results in shocks and vibrations of the gun.

If now the pre-throttling nozzle 17 is installed into the recoil booster according to the present invention ahead of the throttling nozzle 16, then the gas surge is throttled before it exerts an impulse on the front face of the barrel rear section 12. The gas surge expands within the gascollecting sleeve G so that the impulse becomes softer, yet lasts for sufiicient length of time until the complete recoil of the barrel rear section 12 is terminated. The length of the recoil impulse is maintained by the throttle nozzle 16 in front of the gas-collecting sleeve G. When the complete recoil of the barrel rear section 12 is reached, then the forward end of the recoiling barrel rear section 12 opens up the lateral gas discharge channel 19 and the remaining gases escape in part through the channel 19 into the atmosphere and in part through the throttle nozzle 16 into the bore of the barrel front section 10. Also, this discharge may be lengthened if one exchanges the throttle nozzle 16 with one having a smaller nozzle diameter. The cadence of the gun is thereby decreased.

While I have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art; and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. A recoil booster for blank-cartridge practice firing of recoiling heavy and very heavy machine guns, comprising:

barrel means subdivided into a front barrel section and into a rear barrel section separate from said front barrel section,

throttling nozzle means mounted at the rear end of the bore of the front barrel section,

and pre-throttling nozzle means arranged at the front end of the rear barrel section.

2. A recoil booster for blank-cartridge practice firing of recoiling heavy and very heavy machine guns, comprisbarrel means subdivided into a front barrel section and into a rear barrel section separate from said front barrel section,

said front barrel section being provided at the rear end thereof with chamber means forming a gas-collecting chamber,

said front barrel section being slidably mounted with said chamber means over the front end of the rear barrel section,

throttling nozzle means mounted at the rear end of the bore of the front barrel section,

and pre-throttling nozzle means arranged at the front end of the rear barrel section.

3. A recoil booster for blank-cartridge practice firing of recoiling heavy and very heavy machine guns, COIHPIIS- barrel means subdivided into a front barrel section and into a rear barrel section separate from said front barrel section,

said front barrel section being provided at the rear end thereof with chamber means forming a gas-collecting chamber,

said front barrel section being slidably mounted with said chamber means over the front end of the rear barrel section,

throttling nozzle means mounted at the rear end of the bore of the front barrel section,

pre-throttling nozzle means arranged at the front end of the rear barrel section,

and means for controlling the length of recoil movement of said rear barrel section including discharge means in the walls forming said chamber means which are valved by said barrel front section.

4. A recoil booster for blank-cartridge practice firing of recoiling heavy and very heavy machine guns, comprismg:

a relatively fixed gun casing,

barrel means subdivided into a front barrel section and into a rear barrel section separate from said front barrel section,

said front barrel section being provided at the rear end thereof with an enlargement forming a gas-collecting chamber,

said front barrel section being slidably mounted with said enlargement over the front end of the rear barrel section,

throttling nozzle means mounted at the rear end of the bore of the front barrel section,

pre-throttling nozzle means arranged at the front end of the rear barrel section,

and means threadably connecting said barrel front sec tion with said casing.

5. A recoil booster for blank-cartridge practice firing of recoiling heavy and very heavy machine guns, comprismg:

a relatively fixed gun casing having an outwardly directed flange,

barrel means subdivided into a front barrel section and into a rear barrel section separate from said front barrel section,

said front barrel section being provided at the rear end thereof with an enlargement forming a gas-collecting chamber,

said front barrel section being slidably mounted with said enlargement over the front end of the rear barrel section,

throttling nozzle means mounted at the rear end of the bore of the front barrel section,

pro-throttling nozzle means arranged at the front end of the rear barrel section,

and means threadably connecting said barrel front section with said casing including a nut threadably secured over the rear end of said barrel front section, a counter nut threadably secured to said first-mentioned nut, and spacer means between said flange and said counter nut.

6. A recoil booster for blank-cartridge practice firing of recoiling heavy and very heavy machine guns, comprising:

a relatively fixed gun casing,

barrel means subdivided into a front barrel section and into a rear barrel section separate from said front barrel section,

said front barrel section being provided at the rear end thereof with an enlargement forming a gas-collecting chamber,

6 said front barrel section being slidably mounted with is formed by and said mounting means includes one of said enlargement over the front end of the rear barsaid barrel sections having a hollow outwardly opening rel e tion, tubular steering portion adjacent to and telescopically rethrottling nozzle means mounted at the rear end of the ceiving the adjacent end of the other of said barrel secbore of the front barrel section, 5 tions, said sleeve portion having an internal diameter pre-throttling nozzle means arranged at the front end greater than and an extension of the bore portion in said of the rear barrel section, one of said barrel sections to constitute said sleeve pormeans for controlling the stroke of recoil movement tion a working chamber and said adjacent end of the other of said barrel rear section, of said barrel sections a piston. and means threadably connecting said barrel front sec- 10 11. The device of claim 10, including gas discharge tion with said casing. channel means in said sleeve portion for venting the gasses 7. A recoil booster for blank cartridge practice firing from said chamber means only after said sections have of recoiling heavy and very heavy machine guns, commoved a substantial distance from said normal position prising: to said recoil position, and for being closed by said piston a relatively fixed gun casing having an outwardly diin said normal position and opened in said recoil position. re ted flange, 12. The device of claim 11, wherein said sleeve portion barrel means subdivided into a front barrel section and is on said front barrel section and has a threaded portion into a rear barrel section separate from said front on its exterior; a nut-threaded onto said sleeve portion and barrel section, having a rearwardly opening externally threaded tubular said front barrel section being provided at the rear end portion; a fixed barrel casing surrounding said rear barthereof with an enlargement forming a gas-collecting rel section, telescoped at its forward end into said nut h b r, tubular portion and having a radially outwardly extendsaid front barrel section being slidably mounted with ing flange means; an additional nut threaded onto said first said enlargement over the front end of the rear barmentioned nut and having a radially inwardly extending rel section, flange means rearward and radially inwardly of said first throttling nozzle means mounted at the rear end of the mentioned flange means for rigidly mounting said barrel bore of the front barrel section, casing to said rear barrel section. pre-throttling nozzle means arranged at the front end 13. The device of claim 8, wherein said chamber means of the rear barrel section, is formed by and said mounting means includes one of and means threadably connecting said barrel front secsaid barrel sections having a hollow outwardly opening tion with said casing including a nut threadably setubular sleeve portion adjacent to and telescopically recured over the rear end f S barrel front Section, cciving the adjacent end of the other of said barrel seca counter nut threadably secured to said first-mentions, said sleeve portion having an internal diameter tioned nut, and spacer means between said flange and greater than and an extension of the bore portion in said said counter nut, means for controlling the stroke of one of said barrel sections to constitute said sleeve porrecoil movement of said barrel e Section including tion a working chamber and said adjacent end of the other discharge aperture means in said nut and in the porf id b rr l e tion a iston, tion of said chamber wall which is valv d by ai 14. The device of claim 13, including a gas discharge barrel front section. channel means in said sleeve portion for venting the gasses 8- A recoil booster 3 Weapon having automatic 4 from said chamber means only after said sections have recoil elements comprising: moved a substantial distance from said normal position to a barrel havinga bore; said recoil position, and for being closed by said piston said barrel including a front e ti n having a fi P in said normal position and opened in said recoil position of said bore and an aligned separate rear section i having a second Portion of sfaid bPre; 15. The device of claim 8, including means for removfirst throttling nozzle means 1n sa1d first bore portion; ably mounting each of Said throttling nozzle means for separate second throttllng nozzle means 1n sa1d second replacement to change the gas pressure within Said cham bore P ber means during firing and the resulting recoil characrneans for mounting said front and rear barrel sections teristiw for relative movement generally parallel to said bore References Cited between a normal position and a recoi position; gas collecting chamber means in fluid communication UNITED STATES PATENTS with said bore downstream of said second throttling 606,115 6/1898 Benet 89-14 means and upstream of said first throttling mean 682,230 9/1901 Perino 89-14 relative to the travel of combustion gasses in said 1,671,327 5/1928 Studler 89-14 bore from said rear section to said front section, for FOREIGN PATENTS driving said front and rear sections relative to each other from said normal position to said recoil position with a force correlated with the gas pressure within said chamber means to actuate the automatic 6U recoil elements during firing of the weapon.

9. The device of claim 8, wherein said first throttling nozzle means is in the rearmost portion of said first bore portion and said second throttling nozzle means is in the BENJAMIN BORCHELT Primary Exa'mmerforwardmost portion of said second bore portion. S. C. BENTLEY, Assistant Examiner.

10. The device of claim 9, wherein said chamber means 227,570 5/ 1963 Austria. 419,708 10/ 1925 Germany. 1,172,993 6/1964 Germany.

21,843 3/ 1913 Great Britain. 1,190,362 4/1965 Germany. 

1. A RECOIL BOOSTER FOR BLANK-CARTRIDGE PRACTICE FIRING OF RECOILING HEAVY AND VERY HEAVY MACHINE GUNS, COMPRISING: BARREL MEANS SUBDIVIDED INTO A FRONT BARREL SECTION AND INTO A REAR BARREL SECTION SEPARATE FROM SAID FRONT BARREL SECTION, THROTTLING NOZZLE MEANS MOUNTED AT THE REAR END OF THE BORE OF THE FRONT BARREL SECTION, AND PRE-THROTTLING NOZZLE MEANS ARRANGED AT THE FRONT END OF THE REAR BARREL SECTION. 